Dates dating back 20th centuries should be indicated as Hijri/Common Era (H/CE).

Misuse: Abū Isḥāq Ibrāhīm al-Ṣaffār al-Bukhārī (d. 1139)

 Correct Use: Abū Isḥāq Ibrāhīm al-Ṣaffār al-Bukhārī (d. 534/1139)

Dates are written without abridging them:

Misuse: 1810-11| 1914-15

 Correct Use: 1810-1811| 1914-1915